An electroforming method is suitable for mass production and is used in manufacturing various components. For example, a conductive film is deposited on the surface of resin onto which the shape of a prototype is impress-patterned, thereby manufacturing a clock hand (for example, see Patent Document 1).
As a method of impress-patterning a prototype into resin, a hot press molding method is known (for example, see Patent Document 1). In the hot press molding method, resin is heated to a glass transition temperature or higher and softened, and the prototype is pressed to impress-pattern the shape of the prototype into the resin. According to the hot press molding method, the shape of the prototype can be impress-patterned into the resin with nanometer dimensions and nanoscale accuracy.
In recent years, as a mold for manufacturing a component or die having a fine shape, a mold using a silicon process is used. As a method of manufacturing a mold used for an electroforming method using a silicon process, a LIGA (Lithographic Galvanoformung Abformung) method is widely known. In the LIGA method, a resist material, such as PMMA (polymethylmethacrylate), is used to coat on an electrode, and synchrotron radiation is irradiated onto the resist material within a region of a desired shape to expose the resist material. After the resist material is developed, electroforming is executed, thereby manufacturing a fine structure having a desired fine shape (for example, Non-Patent Document 1). An example is known in which the LIGA method is repeatedly executed multiple times to form a multistage structure, such as a gearshift (for example, see Patent Document 2). In addition, a UV-LIGA method is used in which a resist pattern is formed by ultraviolet light, which is used in a general semiconductor exposure apparatus, instead of expensive synchrotron radiation, which is used for the LIGA method. In the case of the mold for the electroforming method manufactured by the LIGA method or the UV-LIGA method, no electrode is provided on the side wall of the mold, and an electroformed object is deposited from the bottom surface of the mold. For this reason, even if a structure with a high aspect ratio is manufactured by the electroforming method, a good component with no air bubbles or defects inside the electroformed object can be formed. Like the technology described in Patent Document 2, by repeatedly executing the UV-LIGA method multiple times, a multistage shape can be manufactured.
According to the technology described in Patent Document 3, resist coating and exposure are repeatedly executed multiple times, and then development is executed. In this way, a resist mold having a multistage structure is formed. In this case, a multistage portion is used as a pattern for a monitor with different thickness of the electroformed object.
[Patent Document 1] JP-A-52-60241
[Patent Document 2] JP-A-11-15126
[Patent Document 3] JP-A-10-245692
[Non-Patent Document 1] W. Ehrfeld: IEEE, Micro Electro Mechanical System Proceedings PP86, 1994